High-resolution magnetic resonance imaging for the follow-up of intracranial arterial dissections.

High-resolution magnetic resonance imaging (HRMRI) with a 3-T system can be utilized to identify intracranial arterial dissections (ICADs) as it reveals more than three key features with better clarity than other conventional imaging modalities. This study aimed to assess the changes in the key features of ICADs on HRMRI over time. We screened patients who had undergone HRMRI within 7 days of symptom onset for the evaluation of characteristics associated with intracranial steno-occlusive lesions. Among them, patients who (1) were diagnosed with ICAD based on HRMRI findings and (2) underwent follow-up HRMRI 3-12 months after the initial HRMRI were included in the final study. Baseline HRMRI revealed an intramural hematoma, a flap, and a double lumen in 17 (100%), 15 (88%), and 10 (59%) individuals, respectively. At the 3-months follow-up, an intramural hematoma was still observed in two patients; however, there were various changes in the double lumen and intimal flap. At the 6-months follow-up, an intramural hematoma was not observed in most patients, whereas the double lumen and intimal flap persisted in most patients. The 9-months follow-up displayed distinct differences from the initial status, whereas the 12-months follow-up exhibited no intramural hematomas, intimal flaps, or double lumens in most patients. In those with ICAD, radiological changes were observed between the initial HRMRI and subsequent HRMRI. Moreover, typical ICAD features were hardly retained at the 1-year follow-up. These changes might reflect dynamic processes, including the healing state of the patients.